This invention relates generally to methods for the modification of textile and other materials, for example by the attachment of hydrophobic moieties, to impart properties thereon such as water repellency and permanent press.
Most chemical research in the textile field was conducted in the 1950s, 60s, and 70s. This work has been extensively reviewed. For example, see: Smith and Block, Textiles in Perspective, Prentice-Hall, Englewood Cliffs, N.J., 1982; Handbook of Fiber Science and Technology, Marcel Dekker, New York, N.Y., Vols. I-III, 1984; S. Adanur, Wellington Sears Handbook of Industrial Textiles, Technomic Publishing Company, Inc., Lancaster, Pa., 1995; and Philip E. Slade, Handbook of Fiber Finish Technology, Marcel Dekker, New York, 1998). A large majority of this published research was never commercialized due to inhibitory costs or the impracticality of integration into textile production processes. There has been less research in this area in recent years. Most current work is centered on optimizing existing technology to reduce costs and comply with recent government regulations.
Methods have been developed in the art for making textile materials water repellent. The terms xe2x80x9cwater repellentxe2x80x9d and xe2x80x9cwaterproofxe2x80x9d are distinguishable as related to textiles. Water repellent fabrics generally have open pores and are permeable to air and water vapor. Waterproofing involves filling the pores in the fabric with a substance impermeable to water, and usually to air as well. For the purpose of everyday clothing, water repellent fabric is preferable because of the comfort afforded by the breathability of the clothing.
Current commercial processes for producing water repellent fabrics are based on laminating processes (C. J. Painter, Journal of Coated Fabrics, 26:107-130 (1996)) and polysiloxane coatings (Philip E. Slade, Handbook of Fiber Science and Technology, Marcel Dekker, New York, N.Y., Vol. II, 1984, pp. 168-171). The laminating process involves adhering a layer of polymeric material, such as Teflon(copyright), that has been stretched to produce micropores, to a fabric. Though this process produces durable, water repellent films, it suffers from many disadvantages. The application of these laminants requires special equipment and therefore cannot be applied using existing textile processes. Production of the film is costly and garments with this modification are significantly more expensive than their unmodified counterparts. The colors and shades of this clothing can be limited by the coating laminate film color or reflectance. Finally, clothing made from this material tends to be heavier and stiffer than the untreated fabric. This material also can be disadvantageous due to mismatched expansion and shrinkage properties of the laminate. Polysiloxane films suffer from low durability to laundering which tends to swell the fabric and rupture the silicone film.
Methods of imparting hydrophobic character to cotton fabric have been developed including the use of hydrophobic polymer films and the attachment of hydrophobic monomers via physi- or chemisorptive processes. Repellents used based on monomeric hydrocarbon hydrophobes include aluminum and zirconium soaps, waxes and waxlike substances, metal complexes, pyridinium compounds, methylol compounds, and other fiber reactive water repellents.
One of the earliest water repellents was made by non-covalently applying water soluble soap to fiber and precipitating it with an aluminum salt. J. Text. Res. 42:691 (1951). However, these coatings dissolve in alkaline detergent solution, therefore washfastness is poor. Zirconium soaps are less soluble in detergent solutions (Molliet, Waterproofing and Water-Repellency, Elsevier Publ. Co., Amsterdam, 1963, p. 188); however, due to the non-covalent attachment to the fabric, abrasion resistance and wash fastness are poor. Fabric also has been made water repellent by coating it with a hydrophobic substance, such as paraffin. Text. Inst. Ind. 4:255 (1966). Paraffin emulsions for coating fabrics are available, for example, Freepel(copyright) (BF Goodrich Textile Chemicals Inc., Charlotte, N.C.). Waxes are not stable to laundering or dry cleaning. Durability is poor due to non-covalent coating of the fabric and breathability is low.
Quilon chrome complexes polymerize to form xe2x80x94Crxe2x80x94Oxe2x80x94Crxe2x80x94 linkages (R. J. Pavlin, Tappi, 36:107 (1953)). Simultaneously, the complex forms covalent bonds with the surface of fibers to produce a water repellent semi-durable coating. Quilon solutions require acidic conditions to react thus causing degradation of the fiber through cellulose hydrolysis. Fabric colors are limited by the blue-green coloration imparted by the complex.
Pyridinium-type water repellents have been reviewed by Harding (Harding, J Text. Res., 42:691 (1951)). For example, an alkyl quaternary ammonium compound is reacted with cellulose at elevated temperatures to form a durable water-repellent finish on cotton (British Patent No. 466,817). It was later found that the reaction was restricted to the surface of the fibers (Schuglen et al., Text. Res. J., 22:424 (1962)) and the high cure temperature weakened the fabric. Pyridine liberated during the reaction has an unpleasant odor and the fabric had to be scoured after the cure. The toxicological properties of pyridine ended its use in the 1970s when government regulations on such substances increased.
Methylol chemistry has been extensively commercialized in the crosslinking of cellulose for durable press fabrics. N-methylol compounds are prepared by reaction of an amine or amide with formaldehyde. Alkyl-N-methylol compounds can be reacted at elevated temperatures in the presence of an acidic catalyst with the hydroxyl groups of cellulose to impart durable hydrophobic qualities to cotton. British Patent Nos. 463,300 (1937) and 679,811 (1952). The reaction with cellulose is accompanied by formation of non-covalently linked (i.e., non-durable) resinous material, thus decreasing efficiency. In addition, the high temperature and acid catalyst reduces the strength of the fabric. Recently, the commercial use of methylol compounds has been decreasing due to concerns of toxic formaldehyde release from fabrics treated in such a manner.
Long-chain isocyanates have been used to hydrophobically modify cotton. British Patent No. 461,179 (1937); Hamalainen, et al., Am. Dyest. Rep., 43:453 (1954); and British Patent No. 474,403 (1937)). The high toxicity of isocyanates and significant side reactions with water, however, precluded it from commercial use. To circumvent the water sensitivity of isocyanates, alkyl isocyanates were reacted with ethylenimine to yield the less reactive aziridinyl compound which was subsequently reacted with cellulose. German Patent No. 731,667 (1943); and British Patent No. 795,380 (1958). Though the toxicity of the aziridinyl compound was reduced compared to the isocyanate, the procedure still required the handling of toxic isocyanate precursors. Also, the high cure temperature weakened the cellulose and crosslinkers were needed to increase structural stability. Alkyl epoxides have been reacted with cellulose under acidic or basic conditions to produce water repellent cotton. German Patent No. 874,289 (1953). Epoxides are, in general however, not very reactive and require long reaction times at high temperatures and therefore have not been extensively commercialized.
Acylation of cotton with isopropenyl stearate from an acidic solution of benzene and curing was used to produce a hydrophobic coating for cotton. U.S. Pat. No. 4,152,115. The high cure temperature and acid catalyst however weakens the cotton. This method disadvantageously uses carcinogenic and flammable solvents. The practicality of using flammable solvents in fabric finishings is limited. Alkyl vinyl sulfones have been reacted with cellulose in the presence of alkali to form a water repellent finish. U.S. Pat. No. 2,670,265. However, this method has not been commercialized because the alkali is not compatible with cross-linking reactants required for permanent press treatments.
Methods have been developed for imparting grease repellent properties to materials such as cotton. Perfluoroalkanoic acids have been applied in a variety of ways including as chromium complexes and as quaternary amines. U.S. Pat. No. 2,662,835; Phillips et al., Text. Res. J., 27:369 (1957); Tripp et al., Text. Res. J., 27:340 (1957); and Segal et al., Text. Res. J., 28:233 (1958). Since these finishes are non-covalently linked to the fabric, they are not durable to laundering. Attempts were made to covalently link fluorocarbons to cotton with perfluorinated acid chlorides in the presence of the base pyridine and dimethylformamide solvent (Benerito et al., Text. Res. J., 30:393-399 (1960)), however significant problems were encountered. The pyridine base formed an insoluble complex with the acid chloride that could only be overcome with the addition of large excesses of pyridine or the solvent dimethylformamide. Also, the finish was readily subject to hydrolysis and not durable to laundering. Repellent finishes made by reaction of glycidyl ethers of 1,1-dihydrofluoroalkanols with cellulose (Berni et al., Text. Res. J., 30:576-586 (1960)) produced a more durable finish, but required a reaction time of 30 h at 100xc2x0 C. and were not extensively commercialized. Interest in monomeric fluorocarbon finishes has been superseded by the use of fluorinated polymer films.
Methods also have been developed for modifying cotton by crosslinking in order to impart permanent press properties to the material. These methods have been reviewed in: R. M. Rowell and R. A. Young, Eds., Modified Cellulosics, Academic Press, New York, 1978; M. Levin and S. Sello, Eds., Handbook of Fiber Science and Technology, Vol. 2, Part A, Marcel Dekker, New York, 1984, pp. 1-318; and G. Hermanson, Bioconjugate Techniques, Academic Press, San Diego, Calif., 1996, pp. 169-297. The covalent crosslinks prevent the cellulose chains from slipping, thus imparting high durable press characteristics. However, the short and stiff crosslinks cause the cotton structure to become brittle and display poor tear strength. A variety of textile resins have been developed to crosslink cellulose and impart durable-press properties, such as polymethylol compounds formed by the reaction of aldehydes with amines. They include melamineformaldehyde (British Patent Nos. 458,877, 466,015 and 468,677), dimethylolethyleneurea (U.S. Pat. Nos. 2,416,046, 2,416,057, 2,425,627, 2,436,311, 2,373,136, and 2,899,263; and British Patent Nos. 603,160 and 577,735), and urons/triazones (U.S. Pat. Nos. 2,373,135; and 2,321,989; British Patent Nos. 575,260 and 845,468; German Patent No. 1,123,334; Angew. Chem., 60:267 (1948); Am. Dyest. Rep., 48:44 (1959); and Tex. Res J., 29:170 (1959).
Dimethyloldihydroxyethyleneurea (DMDHEU) has been used in the production of durable-press garments. Text. Res. J., 51:601(1981). However, the DMDHEU system retains chlorine and causes yellowing and tendering of the cloth; therefore it is not suitable for use with white cloth. Resins have been developed specifically for use with white cloth that are esters of carbamic acid (carbamates). U.S. Pat. Nos. 3,639,455, and 4,156,784; Japanese Patent No. 599,505; British Patent Nos. 1,227,366, and 1,523,308; and French Patent Nos. 1,576,067 and 7,532,092. The crosslinking of the cellulose and polymerization of the resin generally occurs at the same time on the fabric. U.S. Pat. Nos. 5,447,537, 4,975,209, 4,936,865, 4,820,307, and 3,995,998.
Methods for modifying materials with reactive groups such as hydroxyls and amines have been developed in the art, however, materials with hydroxyl groups, including polysaccharides such as cellulose, have been found to be difficult to covalently modify and therefore require reactive modifiers or extreme conditions. Methods of reacting with hydroxyls that have been developed in the chemistry field include the use of acid chlorides, anhydrides, succinimides, and carbonyldiimidazole. See, e.g., J. March, xe2x80x9cAdvanced Organic Chemistry-Reactions, Mechanisms and Structure,xe2x80x9d, 3rd Ed., John Wiley and Sons, New York, 1995; and G. Hermanson, xe2x80x9cBioconjugate Techniques,xe2x80x9d Academic Press, Inc., San Diego, 1996.
There is a need for methods for modifying various substrate materials, such as textile fibers of cotton or other cellulosic materials, wool, silk and other proteinaceous fibers, and various other natural, man made, regenerated and synthetic fiber materials to alter and optimize their properties for use in different applications. There is a need for methods for improving the properties of cloth or fabric materials containing various natural, man made, regenerated and/or synthetic fibers of various types, in order to improve various performance properties such as water resistance, soil resistance, speed of drying and permanent press properties. There further is a need for methods for producing modified textile fiber materials and other substrates which may be used in a wide range of applications including clothing and apparel fabrics, and various items of apparel, socks and hosiery, and fabrics for footwear and comfort and shoes, home furnishing fabrics for upholstery and window treatments including curtains and draperies, and fabrics for outdoor furniture and equipment, as well as for industrial textile end uses.
Provided are methods of modifying various substrate materials to alter the properties of the materials. Also provided are a variety of materials produced by the methods disclosed herein. In particular, compositions and methods are provided that permit the modification of a variety of textile fiber materials and similar substrates to alter properties including water repellency, grease repellency, soil resistance, oil or grease resistance, permanent press, detergent free washing, increased speed of drying, and improving strength and abrasion resistance, and to improve comfort, where such fibers are used alone, or in combinations or blends with one or more of the others before or after treatment.
In one embodiment, provided are methods of modifying a material to increase its hydrophobicity as well as a variety of products obtained using the methods. The material which is modified may comprise, for example, a carbohydrate or protein, and the modifiable functional groups on the material may comprise hydroxyls, or amino acid side chains.
In one embodiment, a method of modifying a textile material, for example, a cellulosic, such as cotton, or regenerated or man made cellulosic, or a synthetic polyamide such as nylon, or a natural polyamide, such as wool or a regenerated protein, is provided, the method comprising attaching a multifunctional polymer to the material, wherein the multifunctional polymer comprises hydrophobic groups and hydrophilic groups. The multifunctional polymer may be attached to the material noncovalently via noncovalent interactions between the polymer and the material. The multifunctional polymer may comprise reactive groups, and thus may be attached to the material covalently by reaction of reactive groups on the polymer with reactive groups on the material. Reactive groups include amine, hydroxyl, carboxyl, amide, beta-ketoester, aldehyde, anhydride, acyl chloride, carboxylic acid hydrazide, oxirane, isocyanate, and methylolamide groups. The textile material may comprise, e.g., a hydrophobic or hydrophilic surface.
The multifunctional polymer may be a copolymer comprising hydrophobic and hydrophilic regions. The multifunctional polymer may be formed, for example, by polymerization of hydrophobic monomers and hydrophilic monomers. In one embodiment, the multifunctional polymer is a polysaccharide modified by the covalent attachment of a molecule comprising hydrophobic groups, or a poly(amino acid) modified by the covalent attachment of a molecule comprising hydrophobic groups. The multifunctional polymer may comprises a comb or graft copolymer, for example, with a hydrophobic synthetic polymer backbone and hydrophilic groups grafted thereto. For example, the synthetic polymer backbone may comprise a polymer such as a polyester, polypropylene, polyethylene or copolymer thereof, and the grafted hydrophilic groups may comprise polypeptide or polysaccharide moieties.
A variety of multifunctional polymers are provided. The multifunctional polymer may comprise a hydrophilic polymer comprising a plurality of reactive groups. In another embodiment, the multifunctional polymer may comprise polymerized monomers, such as 2-(acetoacetoxy)ethyl methacrylate, N-acroyloxysuccinimide, acrolein, acrylic anhydride, allylsuccinic anhydride, citraconic anhydride, 4,4xe2x80x2-hexafluoro-iso-propylidenebisphthalic anhydride, methacrylic anhydride, 4-methacryloxyethyl trimellitic anhydride, acryloyl chloride, methacryloyl chloride, adipic acid dihydrazide, allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, xcex1,xcex1-dimethyl-3-isopropenylenzyl isocyanate, N-methylolacrylamide, and N-methylolmethacrylamide.
The multifunctional polymer may comprise a polymer such as a polyacetal, polyacrolein, poly(methyl isopropenyl ketone), poly(vinyl methyl ketone), poly(ethylene glycol) modified to comprise aldehyde groups, poly(ethylene glycol) modified to comprise carbonyldiimidazole groups, poly(acrylic anhydride), poly(alkalene oxide/maleic anhydride) copolymers, poly(azelaic anhydride), poly(butadiene/maleic anhydride) copolymers, poly(ethylene/maleic anhydride) copolymers, poly(maleic anhydride), poly(maleic anhydride/1-octadecene) copolymers, poly(vinyl methyl ether/maleic anhydride) copolymers, poly(styrene/maleic anhydride) copolymers, poly(acrylolyl chloride), poly(methacryloyl chloride), chlorinated polydimethylsiloxane chlorinated polyethylene, chlorinated polyisoprene, chlorinated polypropylene, chlorinated poly(vinyl chloride), poly(ethylene glycol) modified to comprise epoxides, poly(ethylene glycol) modified to comprise isocyanate groups, poly(glycidyl methacrylate), poly(acrylic hydrazide/methyl acrylate) copolymers, succinimidyl ester polymers, poly(ethylene glycol) modified to comprise succinimidyl ester groups, poly(ethylene glycol) modified to comprise tresylate groups, and poly(ethylene glycol) modified to comprise vinyl sulfone groups.
In one embodiment, a method of modifying a material is provided, the method comprising attaching a multifunctional polymer to the material, wherein the multifunctional polymer is capable of non-covalently or covalently binding the material, and wherein the multifunctional polymer is a modified poly(maleic anhydride) polymer. The multifunctional polymer may be attached to the material covalently via a reaction between functional groups on the polymer and the material, or noncovalently via noncovalent interactions between the polymer and the material.
The modified poly(maleic anhydride) polymer may comprise a poly(maleic anhydride) polymer modified by the covalent attachment of a hydrophobic molecule. In one embodiment, the modified poly(maleic anhydride) polymer comprises anhydride groups, and the polymer comprises hydroxyl or amino groups, and the polymer is attached to the material via the formation of ester or amide bonds between the polymer and the material.
The modified poly(maleic anhydride) polymer may be formed by the reaction of a poly(maleic anhydride) polymer comprising carboxy or anhydride groups with a hydrophobic molecule comprising a hydroxyl or amine group, thereby to attach the hydrophobic molecule to the poly(maleic anhydride) polymer via an ester or amide bond. The hydrophobic molecule may have, for example, the formula Rxe2x80x94X, where R is a C8-24 hydrocarbon or fluorocarbon, and X is OH or NH2.
In one embodiment, the modified poly(maleic anhydride) is a copolymer of maleic anhydride and a polymerizable molecule, e.g., vinyl, acrylate, methacrylate, styrene, alkyne, glycidyl acrylate, glycidyl methacrylate, vinyl ether (allyl), acrylamide and methacrylamide, comprising a hydrophobic group, for example, a hydroalkylalkene or a fluoralkyl alkene. The modified poly(maleic anhydride) polymer may be formed by copolymerization of maleic anhydride and an alkene comprising a hydrophobic group, optionally followed by hydrolysis of anhydrides on the resulting polymer to form free carboxyl groups on the modified polymer. In another embodiment, the modified poly(maleic anhydride) polymer is a poly(maleic anhydride) polymer comprising covalently attached polyamide groups, such as nylon, wool or silk groups. In another embodiment, the modified poly(maleic anhydride) polymer comprises a poly(maleic anhydride) polymer comprising covalently attached polysaccharide groups, such as dextran, starch or cellulose groups.
Also provided is a method of modifying a textile material, the method comprising attaching an upper critical solution temperature polymer to the material. The multifunctional polymer may be attached to the material noncovalently via noncovalent interactions between the polymer and the material, or the polymer may comprise reactive groups, and the polymer may be attached to the material covalently by reaction of reactive groups on the polymer with reactive groups on the material. Exemplary polymers include poly(ethylene oxide), alkylpoly(ethylene oxide), poly(propylene oxide), poly(vinyl methyl ether), hydroxypropyl acrylate, hydroxypropyl methylcellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, methylcellulose, poly (vinyl alcohol), poly (N-substituted acrylamides), poly (N-acryloyl pyrrolidine), poly (N-acryloyl piperidine), poly (acryloyl-L-amino acid esters), poly(ethyl oxazoline), poly (methacrylic acid), and copolymers and triblock polymers thereof.
The methods disclosed herein may be used to modify various substrate materials, such as textile fibers of cotton or other cellulosic materials, wool, silk and other proteinaceous fibers, and various other natural, regenerated and synthetic fiber materials to alter and optimize their properties for use in different applications. Materials containing various natural, man made and/or synthetic fibers in the form of yarn, cloth or fabric of various types may be modified, in order to improve various performance properties such as water resistance, soil resistance, oil or grease resistance, speed of drying and such permanent press properties as smoothness or wrinkle resistance, and xe2x80x9cwash and wearxe2x80x9d.
Materials comprising cellulose may be modified and are described by way of example. A variety of other materials, such as leather, other polysaccharides or polyamines, also may be modified, for example, to improve their hydrophobicity by the covalent attachment of hydrophobic groups. Cellulose containing materials which may be modified include cotton materials and various types of regenerated cellulose, such as rayon, including viscose rayon and lyocell and other natural celluloses such as linen, ramie and the like, in fiber, yam or fabric form, which may be either undyed or dyed prior to the modification. Hydrophobic cellulosic material can be modified with attached hydrophobic groups to improve properties of the cellulosic substrate such as water resistance and permanent press properties. Proteinaceous fibers including silk, wool, camel""s hair, alpaca and other animal hairs and furs and regenerated protein fibers may be modified, as well as synthetic fibers including polyamides, such as nylon 6 and 66, various polyesters including polyethylene glycol terephthalate and derivatives thereof, and polytrimethylene terephthalate and other synthetic fibers. Various ones of these types of fibers also can be blended with one or more of the others, before or after treatment, e.g., cotton and/or rayon and polyester, or wool and polyester, together, or with silk, linen or rayon added. The modified materials obtained as disclosed herein may be used in a variety of applications, such as the fabrication of clothing and various items of wearing apparel, socks, hosiery, footwear, and shoes, home furnishing fabrics including upholstery and window treatments including curtains and draperies, and fabrics for outdoor furniture and equipment, as well as for other industrial textile end uses.